The part 2 thread sounds like a great idea, so glad you put your hand up @speedy_w_beans
I really want to try to get my original Blackfoot up to 50mph but my better half seems to think working on the house is more important for some reason at the moment...
Thanks again @Jason1145 my son & I had such a blast running all our cars for this thread

Unfortunately this hobby does take up a lot of time, fitting it in with home life & a young family can create some issues. A break is sometimes needed, my batteries are all in storage at the moment & the cars safety tucked up, I wouldn’t sell any of mine but I think Jason was often changing cars in his collection.
Hopefully someone else will be able to keep this thread going, it’s a brilliant idea!

Maybe not!
I was doing some testing with the clearly not working new 120A ESC & found the old trusty 60A suddenly wasn’t working on my only 3s pack, but was fine on 2s. It seems the connections were dirty on that 3s, the 60A started working fine again with it after cleaning them up. I guess maybe is was arcing a bit on full power on my last try.

No official entries unfortunately this time, we did take the Clod with us to the beach (not really has it out since getting the CR-01) It got a blistering 8.7mph but then we found it got 9.1mph in reverse! Could have been a good comedy entry but I’ve wasted enough of Jason’s time already
I must have fried my new 120a ESC on its first outing last time in Thunder Shot (at least it pushed it past 60mph). I only found out testing things as we were packing to go back on holiday so it was only Blackfoot to try back on 3s.
The fastest its run was 49.1mph but the diff was slipping then so I was hoping with that fixed it may have run faster.
Our previous visit was the next try with the fixed diff, it got a few good passes in till the roll that snapped the wheels axle (halfway through the video below).
While fixing that I swapped the 19t pinion for a 16t when I realised how much higher geared it was over Thunder Shot, that ran 57mph with the same 5200 motor & 3s.
Just for reference (not taking tyre ballooning into account) this should be the motor speed at 50mph:
Thunder Shot is 33,000rpm
Blackfoot with 19t is 23,760rpm
Blackfoot with 16t is 29,040 rpm
The second half of the video is with the 16t pinion:
Both the 16t & 19t got almost identical 48mph speeds!
I made that video for myself really I wanted to listen to the passes back to back as there was clearly something very wrong by the end, you can hear & see it pulsing on the power. The first 16t run was a high 47mph but that was it, it only ran the 48 when we tried tweaking the trim throttle trim up a bit as I had a feeling it wasn’t getting full power. All the other runs got progressively faster by a good few mph as things warmed up usually 3rd or 4th being the fastest, so I think there is probably something wrong. It’s the same TX / RX & ESC so the end points shouldn’t have changed. The ESC has done a lot of passes in different cars so is probably getting a bit tired. It did smell a bit nasty at the end of running. But it ran very well on 2s for a good bash right after.
Not sure what to do next, I really want to try to get the truck up to 50mph 4s would do it, but it's kind of fun to try more with 3s!

That motor looks nice obviously get what you pay for, but a bit out if my price range, you can get 3 separate sets of 3s safe GoolRC motor & ESC combos for the price of that motor alone. It would be interesting to see what difference there was when hooked up to the same battery in the same car, but I’m not spending that much to find out!
Interesting about the wing I was thinking it’s probably more the sides of it stabilising the air flow than the rear tires being pushed down, out of all the cars I have in first page (about 8 I think from memory) it was only the Blackfoots that’s went straight every one of the others were a nightmare!
The wing I stuck on this time is a 58416 from a Rising Fighter, I checked my back order history, @Jason1145 you’re right speed running does cost a lot in parts

It would probably be easier to just pick up another used car with a body really. It took a couple of old cars to build it in the first place, I never actually had a proper body, it was a mates car I swapped for a swamp boat I made back in the day. It was just a basher that turns out to be good at speed running. Of course speed running had lead to it being rebuilt a couple more times with all new parts by now!
Looking a pictures of Thunder Shots there seem to be quite a few with big extra wings on very much like the one I stuck on but the instructions don’t show it. I don’t think the one that is integral to the original body would do much.
On a different note, out of interest are those Castle motors 2 pole? I imagine the 50k limit of the GoolRC ones is the electronics pulsing the magnetic field round the can. Its vaguely interesting to see every one of their motors has the same 50k limit & they are all 4pole.

Interesting, thanks! I’m lucky my uncle gave me his old lathe when I was a teenager, but I probably wouldn’t have thought about using it for that without you saying. Though I won’t be doing it for speed running!
Thanks, we were pleased! It is kind of a Triggers broom of a car but it’s been rebuilt using all stock Tamiya parts (less the shocks) so still really the 30 odd year old car in design at least so chuffed it can cope so well with going that fast, with the wing on at least. It’s a shame you can’t get the proper Thunder Shot bodies any more it would be interesting to see if the wing on that actually worked.
I’ll stick with the proper Tamiya pinions in Blackfoot for now at least, would be interesting to see how fast it can go on 3s first, I’m sure the 19t just too tall. Also I think we may have cooked the new 120A ESC already, we were only bashing on 2s & it was smelling nasty. I stuck an old 60A & it ran much better.
The Castle motors sound good, but we’re not even getting to the 50k limit of ours, I think I’d need some special batteries for that & I don’t want to spend that much!

Great thanks! Slowly creeping up, not sure it will get much faster now. I may try running on an empty road now it drives much better just to see if sand slows it at all, but I’m not sure it will make any difference.
Thanks for confirmation on BF pinion drilling, I’ll try a smaller one on the 5200kv then
Good luck with the Rat, I still love that car!
Let me know when you have finished the time machine, I could really use one too

Official﻿ entry:
﻿ Thunder﻿ Shot (Super Dragon body)
4x4
﻿17t pinion ﻿
﻿5200kv 4 pole & GoolRC 120A esc (you could warm your hands from the heat being kicked out by the big ESC fan!)
Boomerang wh﻿eels & tyres all round. ﻿
﻿4s lipo﻿﻿﻿ (2 regular 2s in series)
61.1mph or 98.3k﻿ph
It was good to see how the wing really made a difference, last time I bodged one on & fitted a high torque servo & saver at the same time so didn’t know which made the massive difference to keeping it under control.
Previous best on 3s with 4300kv﻿ was 50.3﻿ mph & with 5200kv was 57.4. ﻿﻿The talk of KV ratings & batteries over the last few pages was very interesting. My 3s is a little 2200 but 65C/130C where as the two 2s batteries are 4000 30C/60C.
We started out back with the 4300kv motor as its max voltage is listed as 12v & the 5200kv is only 9.6v so I was worried about killing the 5200kv. But we only got 56.8mph with 4s on the 4300kv so I put the 5200kv in & nothing melted! Looking at their ratings sheet it seems they just listed the max voltage to give the 50,000rpm no load limit:
Its the first few rows (3650 motors).
I had just been going for bigger is better & just try it up to now but thought a bit more simple , (if slightly backwards) maths could be used, please correct me if I’m wrong:
So I measured with Thunder Shot that the motor does 25 revolutions per meter.
Then at 1m per second it will do 25 rps, or more usefully x 60 = 1500rpm
1mps is 2.2369mph so
33mps = 73.8mph
So at 73.8mph the motor should be doing 33 x 1500 = 49.500rpm
So even with a bit of wheel spin on the sand & ballooning tyres it’s not going to be far off max RPMs.
However Blackfoot with its 19t pinion from the Frog gear set is only doing 18 revolutions per metre, so works out at just about 100mph at 50,000rpm, but with the same 3s & 5200kv motor has only managed a best of 49mph when Thunder Shot got 57mph with lower gearing.
Unfortunately Blackfoot rolled & snapped a new wheel axle on 3s before we could try 4s. But I think I should probably drop down to an 18T or even 16T pinion before trying again. Or just shove in one of the 3674 motors! (Though I think my batteries may be the limiting factor) But all the longer motors have a 5mm shaft so would need the Tamiya pinion drilling out to fit it & I don’t think that would fit with the rules?

The Clod is the only car we haven’t really tried with yet, it was my excuse for getting a second 4300kv goolrc set but I didn’t ever put them in it. I did stick twin regular ESCs in it with a Y lead (after melting the original single ESC in a stupid accident). With the same big 2s lipo & silver cans it ran a lot faster & was a real handful, very hard to stop it wheeling. However when I checked properly it was only actually doing about 9mph so I didn’t bother even entering it! I’m flat out busy rebuilding 1:1s at the moment so haven’t got time to play with it right now nor had a chance to look on here - sorry, but glad to see you have all been getting some great runs in, was fun catching up!
I did pick up a new 120A goolrc ESC that can run up to 6s (& it came with programming card that works on the 60A ESC too). I found time to stick a new diff in Blackfoot & made a proper detachable wing for Thunder Shot for some testing last weekend, unfortunately the weather was very bad so we didn’t have much time for running or trying the other cars with 4s, but we got it running in Thunder Shot, I post up the official entry later when I’ve up loaded the video.

Thanks, yes as you said after our very first go with Tshot in a little carpark you need more space. Thanks hat beach is a bit special, as I’m sure a lot of people find it’s often the slowing down under control that is the problem. As you say its the curbs on roads that kill the cars as well as traffic you need to suddenly avoid!
Its about 80 miles from our house down country roads so is driveable in a day but. Its much better if we are staying over as it gives time for over night tuning, I’d have never got that run in one day, as that the only place to safely test too!
There is an industrial estate about half an hour away I may try Blackfoot at some time after I’ve rebuilt the gearbox again.
I’m only going to keep Tshot & the BF as speed runners now, I should really put my TT-02 high speed gear sets up for sale...

It’s taken the best part of a year to actually get my Thundershot to drive properly at speed but I finally got there last weekend!
It’s been taking a heavy pounding every session, it needed all this after the last try
Its only the blue suspension arms left from the car I started with! I was hoping the new wheels & tyres would help but as you can see from the first few clips on the video it was still bad.
We tried running it first on the Saturday (the first clips) but decided to quit before it got broken again & concentrate on Blackfoot.
My boy was so pleased with Blackfoots run he really wanted to try Thundershot again, I’d about given up with it but luckily listen to him! So the next day he persuaded mum we should go back to the same beach. I took the high torque servo & saver out of Blackfoot & fitted those as the only play left in the steering was in the standard servo horn & saver. I also knocked up up a quick wing to try to give the rear a bit more stability, it worked a treat with a 55mph run on the first try! The only minor issue was keeping the front wheels down, but that was only when he was out running the dog! I have a bit of ally pressing the front bumper down that seems to keep the front down when you’re not accelerating too fast. It was just as well it didn’t roll, there was no way my “BluePeter” wing would have survived!
Official entry:
Thunder﻿ Shot (Super Dragon body)
4x4
﻿17t pinion ﻿
5200kv 4 pole & GoolRC 60﻿A esc (everything did get quite warm this time!)
New Boomerang wh﻿eels & tyres all round. ﻿
﻿3s lipo﻿﻿
57.4mph or 92.4kph
(Previous best with 4300kv was 50.3 mph)
My boy was asking if there was a faster motor we could get as soon as we had that run in the bag! So I told him we will think about 4s over the winter...

We managed to get one last unexpected trip in to out favourite speed run beach. So did actually get a few decent runs in this time, Thundershots will follow but here’s Blackfoots for now.
Official entry:
Original Blackfoot
RWD
5200kv 4 pole
3s lipo
19t pinion (frog gear set)
49.1mph, 79.0kph
My rear suspension running on bearings is keeping the frog drive shafts in fine, but it sounded very much like the diff was slipping even with the frogshot M2.5 bolt mod, I think that robbed some speed but at least it ran this time! It just sounded worse on the runs after & didn’t go any faster so we had to stop.

Sorry very late reply, but as stated they are actually much smaller motors, probably with a number like 2430. That is the physical size 24mm dia x 30mm long.
The 540 size is 3650 (36mm dia x 50mm long), they are the ones I run.
It would be interesting to see what difference a 3660 made, guess that is a 550 size motor & would fit most cars....

Yes we built it like that from new with the parts from the WT-01. I wanted the extra suspension travel, have had a GF-01 & seeing what a difference converting just the rear on that to wide made.
The body on the WT-01 is really my daughters, but its not long before my son takes over the controls! I do occasionally get a look in